GaAsP-GaAs nanowire quantum dots for novel quantum emitters

Lead Research Organisation: University of Warwick
Department Name: Physics

Abstract

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
 
Description TThe main outcome of this project has been the 30 peer reviewed articles, including Nano Letters, Light, Science and Applications, ACS nano, Small, Nanoscale, etc. More than 20 contributions (18 invited talks and seminars and several oral presentations in different conferences). The characterization techniques using advanced electron microscopy and sample preparation via ultramicrotome allowed us to optimise GaAsP nanowire growth, and just zinc-blende phase was obtained. Additionally, our work discovered the presence of a new kind of defect, not previously observed in these structures, which had a detrimental effect in the optical properties of the material. This knowledge allowed the growers to optimize the final step of the growth conditions. Our research contributed to the fabrication of defect-free axial GaAs Quantum dots in self-catalyzed GaAsP nanowires. Up to 50 quantum dots were placed in a single nanowire with sharp interfaces. Further research has been done by embedding quantum dots on nanowire sidewalls allowing their integration into the active region of radial p-i-n junctions to enhance light emission/absorption.
An important outcome of this research is the deep understanding on segregation and self-formed structures. Twin defects in the nanowires breaks the quantum wires into short sections acting as quantum dots. This structural funding was fully support the optical studies. With controlled growth, these features can be exploited to assemble multiple quantum structures in a new dimension within nanowires.
Our research also contributed to the fabrication of Josephson junctions based on InAs semiconducting nanowires and Nb superconducting electrodes by a shadow evaporation scheme for the superconductor electrode, with clear Josephson supercurrent which can be controlled by a bottom gate. The large excess current indicates a high junction transparency.
Exploitation Route These outcomes can be taken forward by national and international academic groups working on the incorporation of nanowires on Si. UK also has an extensive quantum dot academic community that can take the fundamental physics analysis and applications further. Moreover, leading UK industrial activity in the field of nanotechnology and optoelectronics could use these outcomes to develop new devices.
Sectors Electronics,Energy

 
Description The outcomes of this groant will help to maintain/improve UK strenght in the area of nanotechnology, the field of optoelectronic and the rapidly develpment quatum technology research. 'The impact of this work is recorded against grant ref EP/P000967/1'
Sector Electronics,Energy
Impact Types Economic

 
Title Analysed Data for Nanoskived GaAsP/GaAs Heterostructures: PL Spectra Fit Parameters, Geometrical Data from SEM, Transition Energies from Nextnano Simulations 
Description This dataset is used in the research "Improving Quantum Well Tube Homogeneity Using Strained Nanowire Heterostructures". It underpins the findings that the radial quantum well heterostructure, specifically the GaAsP/GaAs core/shell, configuration is able to host highly strained systems that improve optoelectronic homogeneity with a reduced dependence on overall morphological variations. h5 dataset containing 3 groups of analysed data: Photoluminescence (PL) map fitting data: Lasher-Stern-Wurfel (LSW) fitting parameters, coordinates of individual heterostructures within PL map, raw PL spectra and corresponding LSW fitted curves Data from analysed Scanning Electron Microscopy (SEM) images including diameters, coordinates of individual structures, solidity and eccentricity of detected heterostructures Transitions energies from nextnano simulations for 10 eigenvalues at a series of quantum well (QW) widths, L, from L = 3 to 12 nm at differing phosphorous concentrations (P = 44%, 47% and 50%) in the strained systems and in an unstrained system for comparison. Analysis scripts (MATLAB) are also provided, with a readme.txt file for instructions on how to use and replicate figures from the associated manuscript. 
Type Of Material Database/Collection of data 
Year Produced 2023 
Provided To Others? Yes  
URL https://figshare.manchester.ac.uk/articles/dataset/Analysed_Data_for_Nanoskived_GaAsP_GaAs_Heterostr...
 
Title Analysed Data for Nanoskived GaAsP/GaAs Heterostructures: PL Spectra Fit Parameters, Geometrical Data from SEM, Transition Energies from Nextnano Simulations 
Description This dataset is used in the research "Improving Quantum Well Tube Homogeneity Using Strained Nanowire Heterostructures". It underpins the findings that the radial quantum well heterostructure, specifically the GaAsP/GaAs core/shell, configuration is able to host highly strained systems that improve optoelectronic homogeneity with a reduced dependence on overall morphological variations. h5 dataset containing 3 groups of analysed data: Photoluminescence (PL) map fitting data: Lasher-Stern-Wurfel (LSW) fitting parameters, coordinates of individual heterostructures within PL map, raw PL spectra and corresponding LSW fitted curves Data from analysed Scanning Electron Microscopy (SEM) images including diameters, coordinates of individual structures, solidity and eccentricity of detected heterostructures Transitions energies from nextnano simulations for 10 eigenvalues at a series of quantum well (QW) widths, L, from L = 3 to 12 nm at differing phosphorous concentrations (P = 44%, 47% and 50%) in the strained systems and in an unstrained system for comparison. Analysis scripts (MATLAB) are also provided, with a readme.txt file for instructions on how to use and replicate figures from the associated manuscript. 
Type Of Material Database/Collection of data 
Year Produced 2023 
Provided To Others? Yes  
URL https://figshare.manchester.ac.uk/articles/dataset/Analysed_Data_for_Nanoskived_GaAsP_GaAs_Heterostr...
 
Description Nanowire Josephson Junctions 
Organisation Julich Research Centre
Country Germany 
Sector Academic/University 
PI Contribution 1. P. Perla, H. A. Fonseka, P. Zellekens, R. Deacon, Y. Han, J. Kölzer, T. Mörstedt, B. Bennemann, K. Ishibashi, D. Grützmacher, A. M. Sanchez, M.l I. Lepsa, Th. Schäpers. Fully in-situ InAs nanowire Josephson junctions by selective-area growth and shadow evaporation. Nanoscale advances 2021 DOI: 10.1039/D0NA00999G 2. P. Zellekens, R. Deacon, P. Perla, H. A. Fonseka et al., Hard-gap spectroscopy in a self-defined mesoscopic InAs/Al nanowire Josephson junction. Physical Review Applied 2020, 14, 054019
Collaborator Contribution The partner provided very interesting Nanowires Josephson junctions grown by a novel methodology
Impact 1. P. Perla, H. A. Fonseka, P. Zellekens, R. Deacon, Y. Han, J. Kölzer, T. Mörstedt, B. Bennemann, K. Ishibashi, D. Grützmacher, A. M. Sanchez, M.l I. Lepsa, Th. Schäpers. Fully in-situ InAs nanowire Josephson junctions by selective-area growth and shadow evaporation. Nanoscale advances 2021 DOI: 10.1039/D0NA00999G 2. P. Zellekens, R. Deacon, P. Perla, H. A. Fonseka et al., Hard-gap spectroscopy in a self-defined mesoscopic InAs/Al nanowire Josephson junction. Physical Review Applied 2020, 14, 054019
Start Year 2019
 
Description International Women's day 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Contribution; Women in Microscopy as part of International Women's day 2019 in the department of physics, Warwick
Year(s) Of Engagement Activity 2019
 
Description MAS-CDT seminar. Structural Analysis of Stable Defects in III-V Semiconductor Nanowires 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact The Molecular Analytical Science Centre for Doctoral Training (MAS CDT) is an CDT opened in 2014 with funding awarded from the EPSRC.MAS CDT produce a new generation of Analytical Scientists. With the world-leading facilities and expertise at Warwick at their disposal, students will graduate with a unique combination of skills in exploiting synergies between different experimental methods and in harnessing the power of combining data collection with experimental design, statistical analysis, modelling, and simulation. They will become the future leaders in Analytical Science, equipped with a combination of scientific and complementary skills for addressing many of the key industrial and societal challenges faced by the UK.
During term time, MAS CDT host a weekly seminar series, and I was invited to give one.
Year(s) Of Engagement Activity 2019
 
Description Open Days 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Undergraduate students
Results and Impact Open days in the Department of Physics at Warwick University. The use of electron microscopy for nanostructure analysis is demonstrated. This creates a lot of interest when atomic scale imaging is revealed.
Year(s) Of Engagement Activity 2017,2018,2019,2020
 
Description Q and A session with high school students 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact brief Q and A session with high school students at the Bluecoat School, Terry Rd, Coventry CV1 2BA - 9th July 2019
Year(s) Of Engagement Activity 2019
 
Description electron microscopy of nanostructures' 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact mins of fame 'electron microscopy of nanostructures' - Warwick christmas Lectures 3rd Dec 2019, Butterworth Hall, University of Warwick.
Year(s) Of Engagement Activity 2019